const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const { CleanWebpackPlugin } = require('clean-webpack-plugin');

module.exports = {
  entry: './src/index.js',
  output: {
    path: path.resolve('dist'),
    filename: 'bundle.js',
  },
  devtool: 'inline-source-map',
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: 'babel-loader',
      },
    ],
  },
  plugins: [
    // 在构建之前将dist文件夹清理掉
    new CleanWebpackPlugin({
      cleanOnceBeforeBuildPatterns: ['./dist'],
    }),
    // 指定HTML模板, 插件会将构建好的js文件自动插入到HTML文件中
    new HtmlWebpackPlugin({
      template: './src/index.html',
    }),
  ],
  devServer: {
    // 指定开发环境应用运行的根据目录
    static: {
      directory: path.join(__dirname, 'dist'),
    },
    client: {
      logging: 'error',
      overlay: {
        errors: true,
        warnings: false,
      },
    },
    compress: true,
    open: true,
    port: 5500,
  },
};
